This invention relates to improved devices for automatically closing a valve in response to earthquake forces, or other similar vibrational or shock forces.
In the event of an earthquake, great damage can occur as a result of leakage of gas, water, or other fluids upon rupture of a fluid line. For example, escaping gas can cause highly destructive fires or explosions, and escaping water or other liquids can build up in a home or other building in a manner causing damage to furniture, carpets, drapes, and other contents of the building. Various types of valves have been proposed for automatically closing off a stream of fluid in response to the vibrational or other forces of an earthquake, including for example the devices shown in U.S. Pat. Nos. 3,890,933, 2,054,563, 2,158,753, 2,255,965, 3,768,497, and 3,927,689.